Gas tube storage matrix



H. "J GEISLER 2,889,538

Filed Jan. 29. 195:, 2 sheets-sheet 1 INVENTOR HELMUT JOHN GEISLER BY v AGENT June 2, 1959 H. J. GEISLER GAS TUBE! STORAGE MATR'IX 8 2 Sheets-Sheet 2 Filed Jan. 29. 1953 NQI INVENTOR HELMUT JOHN GEISLER AGENT United States Patent GAS TUBE STORAGE MATRIX Helmut J. Geisler, Wappingers Falls, N.Y., assignor to International Business Machines Corporation, New York, N.Y., a corporation of New York Application January 29, 1953, Serial No. 334,053

5 Claims. (Cl. 340-173) This invention relates to memory devices employed for the storage of electrical signals and more particularly to a novel gas tube matrix storage arrangement.

It is an object of this invention to provide a matrix wherein the storage elements comprise cold cathode gas tubes and in which the positions at which signals are stored may be visually determined.

A further object of this invention is to provide a stor-- age matrix which does not require regeneration at periodic intervals and from which the stored information may be repeatedly read out as desired.

It is also an object of this invention to provide a storage matrix of low power consumption which is relatively independent of the variations in storage tube characteristics and which may be operated at speeds not heretofore contemplated with storage systems employing gas tubes.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings, Figs. 1 and 2 taken together constitute a schematic diagram of the improved storage system.

Accounting equipment generally utilizes record cards bearing character representing designations which are sensed to produce electrical impulses at particular time intervals in the cycle of machine operation. These signal impulses are transferred from a record card sensing unit to a storage device from whichthey may be obtained at a later interval to be employed in a calculation process performed during the time interval between reading successive cards or to control a conventional manifesting unit, for example, a card punching unit.

The matrix illustrated in Figs. 1 and 2 constitutes such a storage device and is shown in connection with a schematically represented record sensing unit andmanifesting device.

Referring to Fig. 1, it will be noted that a record card of the well known type having a plurality of vertical columns with the usual ten digit representing positions 0 to 9, is advanced by feed rollers 11 past brushes 12. The cards are fed successively from the usual supply hopper (not shown) to the feed'rollers which convey the cards with their 9's positions first past the sensing brushes 12; A brush is provided for each column on the record card and the brushes are spaced laterally so as to sense concurrently the like digit representing perforations in dilferent columns by making contact with a conductive roller element 13 through the perforations. 13 is energized from a +50 volt source 14 through a brush'15. During the flight of the card as one reading cycle is completed, the brushes 12 successively sense the digits in the 9 row, 8 row, 7 row, etc., and 50 volt impulses are produced in circuits completed by the brushes 12 as contact is made withroller 13 through card perforations and appear at differential times indicative of the particular digit sensed in any particular order column. p

Order lines A, B-N are connected to the brushes 12 The roller element 2,889,538 Patentedv June 2, 1959 read from a card field or group of columns on the record card from which digital information is to be read and stored in the gas tube matrix. Only three orders of the matrix are illustrated to avoid duplication and unnecessary confusion of the drawings as each order is substantially identical.

The storage matrix employs a radio frequency actuated gas switch tube S and a two element cold cathode gas tube T at each storage position. The switch tube S is described in the copending application for United States Letters Patent, Serial No. 306,544, which was filed August 27, 1952, now Patent No. 2,746,831. Briefly, each switch tube S is provided with two electrodes at and b within an envelope c and a third electrode a comprising a conductive metal band embracing the exterior of the envelope adjacent the ends of the two internal electrodes. Application of R.F. energy between the external band electrode d and the two internal electrodes a and 12 produces an auxiliary R.F. discharge through the gas filling which ionizes the gas and, as a consequence, allows flow of low voltage direct current between the two internal electrodes. Controlled application of R.F. energy to the tube may therefore control a direct current circuit including the internal electrodes, and the tube functions as a fast acting switch device.

Each of the aforementioned order lines A, B--N is connected at each digit level of the storage matrix through the internal electrodes 0 and b of a switch tube S to one terminal of a gas tube T. A resistor R of approximately K ohms resistance is connected between this terminal and ground. The opposite terminal of each storage position tube T is connected to a conductor 16 through leads 17, 18 and 19 provided respectively for the order lines A, B-N as shown. The conductor 16 is maintained at a potential of ll5 volts as applied thereto by a source 20 through a normally closed switch 21. A 10K ohm resistor is connected in shunt with the source 20 in order to stabilize the source voltage under varying load conditions as when selected ones of the tubes T. are ignited as will be later described. The volts potential provided by the source 20 and applied across the tubes T through resistors R is below the voltage required to fire any of the tubes T which have a strike voltage range of between and volts.

The storage matrix is provided with ten digit position conductors labeled 0 to 9 which are provided for each of the 0 to 9 digit levels of storage. The conductors 0 to 9 are connected to corresponding electrically isolated plates 24 of a mechanically driven capacity coupled distributor 25. A rotating condenser element 26 of the distributor is connected to an oscillator 27 of suitable output (75- 150 peak volts) operatingin a'frequency range of from 10 to 20 megacycles.

The external'electrodes d of the switch tubes S in each denominational order are connected to the conductors 0 to 9, respectively, pertaining to the particular digit level for which they are provided. Condensers C1 and C2 are connected between respective ones of the internal electrodes a and b of each switch tube S and ground and serve to complete a circuit path for R.F. energy applied to the external band electrode d while also blocking flow to ground of direct current applied to either of the internal electrodes.

The oscillator 27 is coupled through a switch 28 to a conductor 29 and is connected thereby to the external band electrode d of a second group of R.F. switch tubes 0 0 O provided for each denominational order of the matrix. The internal electrodes of the tubes 0 connect each of the order lines A, B'-N with output lines a, b-n, to which corresponding elements 30 of a manifesting unit are connected. The switch tubes 0 are provided with capacitors C1 and C2 connected between the internal electrodes and ground to provide a path for RF. energy in the same manner as switch tube S.

Each of the order lines A, BN is connected to ground through an individual resistor Y and is normally maintained at ground potential through this coupling except at times when a positive differentially timed input pulse is applied from the card feed unit during read in or when a negative pulse is applied from the storage matrix during read out as will be more fully explained. The resistors Y have ohmic values of between 20K and 100K ohms and are adjusted in relation to the value of all of the capacitors C1 connected to the associated order line in order to limit the tendency for direct current signals to remain on the order lines. It has been noted, however, that this tendencyv to maintain the direct current signal potential on the order lines is to a degree beneficial to rapid recovery of the RE switch tubes on open circuit condition.

The rotor element 26 of the capacity distributor 25 is driven in synchronism with the card feed rollers 11 (Fig. 1) so that conductors -9 are sequentially pulsed with RF. energy in synchronism with the advance of a record card 10 through the reading unit and at times coincident with the reading of corresponding digit positions on the record card. In this manner the digit position lines 0-9 are sequentially pulsed with R.F. energy at times when direct current read in impulses of approximately +50 volts may appear on the order lines A, BN. If a +50 volt pulse appears on one or all the lines A, BN at the same time that a particular one of the digit position lines 0 to 9 is pulsed with RF. energy, then the related storage tube T will be rendered conductive to store the particular digit in the proper order position of the matrix. The voltage applied across the electrodes of the tube T when a read in signal is applied is the sum of the +50 volt read in pulse and the ll5 volt bias from source 20 or a total of 165 volts which potential is sufiicient to fire the storage tube T.

In describing the operation of the system, assume, for example, that the digit 29 is to be stored and read out of the matrx. With a record card 19 fed 9 edge first through the sensing unit, brush 12 connected with order line A will contact the roller 13 through a card perforation in the 9 row and a direct current pulse will appear on order line A simultaneously with the instant rotor 26 of the distributor 25 passes capacitor segment 24 connected with the digit level conductor 9. As RF. energy is applied to the conductor 9, each of the switch tubes S associated therewith become conductive and connect the order lines with one terminal of the storage tubes T at this digit level. The +50 volt read in pulse appears only on order line A and the tube T at this position is subjected to a voltage of 165 volts which ignites this storage tube. As the rotor 26 continues to rotate, the RF. energy applied to line 9 is terminated and each of the switch tubes S at the 9 digit level are extinguished, however, the storage tube T which has been ignited by the signal pulse continues to conduct through a path including the source 20 and the associated resistor R. The voltage applied to the ignited tube from source 20 alone is sufficient to maintain conduction in the tube and the potential at the tube side of the resistor R drops to about 50 volts. A representation of the numeral 9 in the units order has now been stored.

Application of successive bursts of energy to the lines 8, 7, 6, 5, 4 and 3 produce no change in the nonconducting state of the tubes T associated therewith. The switch tubes S in each digit level row are ignited, but no signal impulses are applied to the order lines A, BN as no perforations are sensed in the record card at these time intervals for the example taken and the order lines are held at ground potential by the connection through resistors Y. At the instant rotor 26 passes segment 24 connected with lead, 2, however, the order line B is pulsed as brush 12 contacts conductive roller 13 through a card perforation at this time. The signal pulse on line B passes the tube S associated with this order line and tube T at this position is ignited. As rotor 26 leaves the segment 24 connected to lead 2, the tubes 8 energized from this lead are extinguished. However, the ignited storage tube T continues to conduct and the potential at the tube side of the associated resistor R is lowered to 50 volts. A representation of the numeral 2 in the tens order now has been stored. Subsequent R.F. energization of lines 1 and 0 from the distributor 25 produce no change in the nonconducting states of the tubes T at these digit levels as no card perforations are sensed at these time intervals for the example taken. The storage tubes T at the two digit level in the tens order and at the nine digit level in the units order are ignited and the digit 29 is stored in the matrix and may be visually observed.

In reading out the stored number 29, switch 28 is closed either manually as shown or by electronic or electromagnetic means under the control of the manifesting unit so as to initially energize the read out tubes 0 O --O at a time when the rotor 26 of capacitor distributor 25 is positioned between segments 24 connecting the 0 and 9 digit leads. The group of switch tubes S energized from digit level conductor 9 are thus initially rendered conductive on read out. Storage tube T associated with the order line A at this digit level is ignited and the tube side of resistor R at this storage position is maintained at a potential of 50 volts. As the 9 digit level switch tubes S are rendered conductive, each of the order lines A, BN are connected to the tube side of the associated resistors R and the potential of line A is then lowered to a potential of -50 volts. The remaining order lines are uneffected since the tubes T associated therewith at the 9 digit level are not conducting and the tube side of resistors R in their orders are at ground potential. Order line A is connected through the now conductive read out switch tube 0,, and the negative voltage shift on line A is applied to output line a and a time ditferentiated negative pulse at 9 time is applied to the associated operating magnet 30 of the manifesting unit.

Sequential ignition of the switch tubes S at digit levels 8, 7, 6, 5, 4, and 3 fail to produce output signals on the lines a, 12-11 as the potential at the tube side of the resistors R in these digit positions remains at ground level since none of the storage tubes T in these digit rows are ignited. When the switch tubes S at the 2 digit level are ignited, as when rotor 26 passes segment 24 connected with lead 2, the potential of order line B is lowered to approximately 50 volts since the tube T at this storage position is conductive. Order line B is connected through the read out switch tube O to output line b and this negative voltage shift is applied to the operating magnet 30 associated with this output line at 2 time. Further ignition of the switch tubes S at digit levels 1 and 0 fail to produce output signals on line a, 12-11 as none of the storage tubes T at these digit levels are ignited.

The number 29 is thus read out of the storage matrix in the form of differentially timed impulses and, as the read out operation produces no change in the conductive state of the storage tubes T or in the potentials existing at the tube side of the associated resistors R, the information has not been destroyed but may be repeatedly read out as often as desired. Such functioning has utility, for example, where it is desired to record the same data on a plurality of record cards or in performing multiplication by the process of over and over addition.

The storage matrix may be reset prior to storage of further information by momentary opening of the circuit from source 20 which extinguishes all the storage tubes T. Switch 21 may be operated manually as shown or under control of the read out unit by electromagnetic or electronic means to accomplish this purpose.

The invention is not to be considered limited to the particular means shown for application of R. F. energy to the digit position conductors to 9 as this function may be accomplished by other arrangements. It is contemplated, for example, in systems requiring high speed operation, that an oscillator be provided for each digit position line 0-9 and turned on in sequence as determined by an electronically controlled ring circuit. It is also contemplated that a rotating condenser may be employed in the frequency determining circuit of a single oscillator so as to vary the output frequency and with networks resonant at distinct frequencies individually coupling the conductors 0-9 with the oscillator output.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In a system for storage of dilferentially timed electrical impulses representative of digital information, a gaseous discharge storage tube having at least two electrodes, an impedance connected to one of said electrodes, a source of potential connected across said electrodes through said impedance, said source of potential having a voltage intermediate discharge sustaining potential and firing potential of said storage tube, a source of differentially timed electrical impulses, means including radio frequency actuated switch tubes coupling said source of impulses in series with said impedance whereupon receipt of an impulse develops a voltage thereacross additive with respect to said source of potential and sufiicient to fire said storage tube, and means for actuating said switch tubes at an interval coincident with the receipt of certain of said impulses.

2. A memory system for storage of differentially timed electrical impulses representative of digital information comprising a plurality of two element gaseous discharge storage tubes arranged in a coordinate array of columns and rows wherein the number of columns provided corresponds with the denominational orders of a multidigit character to be stored and the number of rows provided corresponds with the number of digital variations in each order, an impedance connected to one electrode of each of said tubes, 2. source of potential having a voltage intermediate discharge sustaining potential and firing potential of said storage tubes, circuit means connecting said source of potential across the electrodes of each of said tubes through said impedances, a source of differentially timed electrical impulses corresponding with the digital information of each order and representative in time of a particular digital value, means for applying said impulses for each order to the impedance elements of the storage tubes in corresponding columns, said latter means including individual radio frequency actuated switching tubes actuated in sequence in each of said order columns at times corresponding with variations in delivery of said differentially timed impulses.

3. A memory system for storage of differentially timed electrical impulses representative of digital information comprising a plurality of two element gaseous discharge storage tubes arranged in a coordinate array of columns and rows wherein the number of columns provided corresponds with the denominational orders of a multidigit character to be stored and the number of rows provided corresponds with the number of digital variations in each order, an impedance connected to one electrode of each of said tubes, a source of potential having a voltage in termediate discharge sustaining potential and firing po tential of said storage tubes, circuit means connecting said source of potential across the elements of each of said tubes through said impedances, a source of differentially timed electrical impulses having a voltage greater than the difference between the voltage of said source of potential and firing potential of said tubes and corresponding with the digital information of each order of said character to be stored, said impulses in each order being representative in time of a particular digital value, means for applying said impulses for each order to the impedance elements of the storage tubes in corresponding ones of said columns including individual radio frequency actuated switching tubes, means for actuating the switching tubes in each order column in sequence at times corresponding with variations in delivery of said differentially timed impulses, said latter means comprising a capacitive pulse distributor device having a mechanically driven rotor element and a number of fixed distributor elements corresponding with the number of said rows of tubes and sequentially capacity coupled with said rotor element at said differential times, and a source of radio frequency energy coupled to said rotor element.

4. A memory system for storage of differentially timed electrical impulses representative of digital information comprising a plurality of two electrode gaseous discharge storage tubes arranged in a coordinate array of. columns and rows wherein the number of columns provided corresponds with the denominational orders of a multidigit character to be stored and the number of rows provided corresponds with the number of digital variations in each order, a resistor connected to one electrode of each of said storage tubes, a source of potential having a voltage intermediate discharge sustaining potential and firing potential of said storage tubes, circuit means connecting said source of potential across the electrodes of said tubes through said resistors, a source of differentially timed electrical impulses having a voltage greater than the difference between the voltage of said source of potential and the firing potential of said storage tubes and corresponding with the digital information of each order of said multidigit character to be stored, said impulses in each order being representative of a particular digital value, means for applying said impulses for each order through the resistors of the storage tubes in corresponding ones of said columns including individual radio frequency actuated switching tubes, means for actuating the switching tubes in each said column in sequence at times corresponding with variations in delivery of said differentially timed impulses, said latter means comprising a commutator device having a mechanically driven capacitor element and a plurality of fixed output capacitor elements one for each of said rows of tubes and sequentially capacity coupled with said mechanically driven capacitor element at said differential times, and means for subsequently ascertaining the voltage drop across said resistors in reading the information stored by the conductive state of said storage tubes comprising further radio frequency actuated switch tubes selectively operable to connect a diiferentially sensitive load device to said resistor elements during an operating cycle of said commutator device.

5. Apparatus for storage of differentially timed electrical impulses representative of digital information comprising a plurality of two electrode gaseous discharge storage tubes, one for each variation in digital value of the information to be stored, individual impedance elements connected to one electrode of each of said tubes, a source of potential having a voltage intermediate discharge sustaining potential and firing potential of said tubes, circuit means connecting said source of potential across the electrodes of each of said tubes through said individual impedances, a source of differentially timed electrical impulses, means coupling said individual impedance elements in parallel through said source of electrical impulses and including individual radio frequency actuated switching tubes, and means for actuating said switching tubes in sequence and in synchronism with variations in delivery time of said differentially timed impulses comprising a capacitative commutating device hav- 7, ingra'meehanieelly driven rotor element anda plurality of adjacent positioned fixed distributor elements capacity coupled therewith, and means for energizing-said rotor element from a single source of radio frequency energy. 5

References Cited in the file of this patent UNITED, STATES PATENTS 2,108,219 Swart Feb. ;15, 1938 10 

